Small Cities, Big Impact: Multi-hazard Exposure Mapping for Prioritizing Climate Action

This is the second blog in a three-part series that presents the climate action planning process for three cities in Maharashtra. Read the first blog in the series here.

Despite efforts to enable climate action, a range of obstacles, including challenges of perception, limit their effectiveness. Climate change tends to be perceived as a distant problem, and climate action often takes a disaster mitigation approach. There is a need to shift from this approach, of recovery post disaster, to preemptive risk reduction and resilience building.

The climate action plan (CAP) process also emphasizes the role of climate adaptation in enhancing urban climate resilience. This calls for a deeper understanding of the nature of climate risks and their impact on people, services and assets. Additionally, despite identifying short, medium and long-term sectoral actions, cities often struggle with determining where to begin and what strategies to prioritize.

Multi-hazard exposure mapping can be used as a prioritization technique to help decision-makers analyze spatial variations and overlaps in climate hazard at-risk areas and deploy adaptation measures accordingly. As WRI India has been supporting four cities in Maharashtra in the preparation of their respective CAPs, this blog looks at this prioritization process and shares the findings from the adopted multi-hazard exposure mapping.

Why Multi-hazard Exposure Mapping?

The Climate Hazard and Vulnerability Assessment (CHVA) is a tool developed by WRI India, through which cities can assess differential vulnerabilities based on varied exposure to climate and disaster risks, pre-existing socio-economic sensitivities, and access to essential services and amenities that are critical for rescue and recovery processes during extreme weather events.

Evaluating the spatial extent, for varying intensities and frequencies of climate hazards, can help determine the areas prone to climate hazards. Multi-hazard exposure mapping can identify areas that face compounding effects of multiple hazard occurrences – sequential, concurrent or cascading.

Further, the multi-hazard exposure mapping of a region can be overlayed with exposure analysis of population, and jobs and civic amenities at risk, based on the ratio of built-up and population in the multi-hazard prone areas. By layering socio-economic data, and infrastructural assets and access to them within the multi-hazard area, city authorities can distinguish the population that is more sensitive to climate hazards and take informed climate actions targeted at the specific nature and consequences of the risk.

Multi-hazard Exposure Mapping in Maharashtra

Multi-hazard exposure mapping in Nashik revealed that 40% of the city’s population is exposed to land surface temperature (LST) above 32 degrees Celsius and 23% of the population lives within waterlogging hotspots. On overlaying the spatial extents of these hazards, it was found that 9% of Nashik city’s population is exposed to both above-average LST and waterlogging. This population is concentrated in the central areas, namely Koknipura, Dudhsagar, Shivneri Chowk and Nashik main bus stop, among others, as seen in Figure 1.

A total of 42 schools and 18 hospitals lie within this region, while 42.5% of informal settlements (located in Koknipura and Wadala Gaon) and 1.9% of industrial areas (Satpur and Ambad) are vulnerable to multiple hazards, including high LST and urban flooding. Adding the layer of traffic hotspots to the multi-hazard exposure analysis highlights the potential air pollution risk, especially in the central part of the city. This additional threat of increased air pollution is attributed to tailpipe emissions from high vehicular movement and rising construction activity in the central areas.

In Solapur, 33% of the population is exposed to above-average LST, while about 10% reside in areas with reduced groundwater recharge potential (GWRP). Overlaying the spatial extents of these hazards reveals that approximately 3.4% of Solapur’s population, mainly in the city’s eastern part, is exposed to both above-average LST and decreased GWRP, as shown in Figure 2. This area has about 19 schools, two hospitals, and 2% of the city’s informal settlements, all of which are at an added risk due to the nature of their vulnerabilities.

Similarly, an analysis of risks in Chhatrapati Sambhajinagar shows that 0.7% of the population is exposed to both above-average LST and waterlogging, primarily in the industrial area of CIDCO and the informal settlement in Shanoorwadi, as depicted in Figure 3.

While all the above multi-hazard exposure maps use a combination of climate data, remote sensing data, census data and GIS-based data from city authorities, it is valuable to collect data from citizen groups, local non-governmental organizations and civil society organizations. Their additional localized knowledge can further highlight differential vulnerabilities. For instance, Nashik city used data from their grievance portal to map the waterlogging hotspots in the city. This publicly sourced data can help city officials conduct such analysis, develop prioritization frameworks and develop strategies based on ground realities.

Multi-hazard exposure mapping for cities in Maharashtra acts as a starting point to analyze the exposure levels spatially, allowing city departments to prioritize areas of intervention. Further, the overlaying of socio-economic, demographic and infrastructure data helps assess the differential vulnerabilities in the multi-hazard-prone areas.

The nature of the compounded risk in areas exposed to multiple hazards is further exacerbated for vulnerable populations such as those living in informal settlements due to poor living conditions and lacking basic services. People working outdoors, such as construction workers and street hawkers, are also physically exposed, which can directly impact their livelihood and health due to the nature of their vulnerability. Combining hazard identification, spatial exposure mapping and socio-economic assessment presents a robust approach to understanding urban vulnerabilities, leading to inclusive, equitable and effective climate action. While a climate hazard and vulnerability assessment for prioritization of strategies is a necessary step, it must be followed by a robust implementation plan.

The next and final blog in this series will present the key pillars that are necessary to move from the planning stage to the implementation stage of climate action plans. Read the first blog of the series on Maharashtra’s climate action planning process here.